** A necessity of perpetual recurrence?

Emerging infections: a perpetual challenge.

Emerging and re-emerging infectious diseases, and their determinants, have recently attracted substantial scientific and popular attention. HIV/AIDS, severe acute respiratory syndrome, H5N1 avian influenza, and many other emerging diseases have either proved fatal or caused international alarm. Common and interactive co-determinants of disease emergence, including population growth, travel, and...

A modified perpetual inventory approach

Many recent studies exploring conditional factor demand or factor substitution issues use firm level panel data. A considerable number of establishment panels contains no direct information on the capital input, necessary for production or cost function estimation. Incorrect measurement of capital leads to biased estimates and casts doubt on any inference on output elasticities or input substit...

Perpetual Trade Liberalization

If the costs of going back on previously agreed tari¤ reductions are high relative to the terms of trade gains, then the multilateral liberalization process becomes ‘perpetual’. Perpetual trade liberalization has two unique characteristics. (i) No ‘e¢cient’ tari¤ level exists at which liberalization stops. (ii) Some liberalization must occur in every period. International agreements and institu...

Veterinary Pharmacy, a Dismissed Necessity

Perpetual Requirements Engineering

This dissertation attempts to make a contribution within the fields of distributed systems, security, and formal verification. We provide a way to formally assess the impact of a given change in three different contexts. We have developed a logic based on Lewis’s Counterfactual Logic. First we show how our approach is applied to a standard sequential programming setting. Then, we show how a mod...